1. Field of the Invention
The present disclosure relates to a Mach-Zehnder modulator,
2. Description of the Related Art
Patent Literature 1 (U.S. Unexamined Patent Application Publication No. 2013/0209023) discloses a Mach-Zehnder modulator.
The Mach-Zehnder modulator in Patent Literature 1 is driven by a differential driver. In the Mach-Zehnder modulator, a pair of signal electrodes, which allows a pair of differential signals to be transmitted, extends in parallel with one arm waveguide and the other aria waveguide, respectively. A pair of signal electrodes is connected to the upper surface of a P-type layer of the one arm waveguide, and the upper surface of a P-type layer of the other arm waveguide, respectively. An N-type layer of the one arm waveguide and an N-type layer of the other arm waveguide are connected to a common conductive plane provided below. The common conductive plane has a floating potential without being connected to the ground electrode. A pair of ground lines extends in parallel with and outwardly of a pair of signal electrodes, thereby forming a transmission line in GSSG structure.